" Nationwide, data centers used about 76 billion kilowatt-hours in 2010, or roughly 2 percent of all electricity used in the country that year, based on an analysis by Jonathan G. Koomey, a research fellow at Stanford University who has been studying data center energy use for more than a decade. DatacenterDynamics, a London-based firm, derived similar figures.

The industry has long argued that computerizing business transactions and everyday tasks like banking and reading library books has the net effect of saving energy and resources. But the paper industry, which some predicted would be replaced by the computer age, consumed 67 billion kilowatt-hours from the grid in 2010, according to Census Bureau figures reviewed by the Electric Power Research Institute for The Times. "

I know very little about technical computer stuff, and never thought that the act of sending and resending documents to myself could be more wasteful than just printing a copy out and carrying it around with me...

if the amount of kW of power it takes to send the extra few bytes of "please consider the environment..." billions of times across the globe is actually more than the amount of people who print out said email. I can't remember ever printing out an email in work?